Split Crest—Is It Necessary to Fill the Gap?—A Controlled Trial

Introduction: The split crest (SC) is a technique for horizontal ridge augmentation that enables simultaneous implant placement. While the use of bone grafts within the osteotomy gap is well-documented, the efficacy of dentin as a graft material in SC procedures has not been thoroughly evaluated. Objective: This study aimed to assess whether the addition of bone graft or dentin to the osteotomy gap during the SC procedure improves bone width, density, and implant stability compared to SC without grafting. Materials and Methods: A partially randomized prospective study was conducted on 24 implants divided into three groups: SC only, SC and bone graft, and SC and dentin graft. Clinical and radiographic evaluations, including CBCT-based bone measurements and implant stability (ISQ) values, were performed preoperatively, immediately postoperatively, and three months after surgery. All patients were followed for one year. Results: Significant increases in bone width were recorded in all groups, with gains exceeding 2 mm in the SC and SC and bone graft groups. The SC and dentin group showed the least bone gain and the greatest horizontal bone resorption (p < 0.05). Conclusions: While bone grafting may offer modest advantages in bone preservation, the use of dentin grafting may not demonstrate significant benefits.